PNNL

Abstract

Classified as a biosafety level 4 select agent, Nipah virus (NiV) is a deadly paramyxovirus with significant potential to cause substantial damage to global human and animal health. The recent findings of over twenty related viruses in the Henipavirus genus likely carried by bat and rodent reservoirs underscore the urgency of Henipaviral research. Elucidating the process of viral particle production in host cells is imperative both for targeted drug design and viral particle-based vaccine development. However, relatively little is understood concerning the functions of cellular machinery in paramyxoviral and henipaviral assembly and budding from host cells. Recent studies showed evidence for the involvement of multiple NiV proteins in viral particle formation, in contrast to the mechanisms understood for several paramyxoviruses as reliant on the matrix (M) protein alone. Further, the levels and purposes of cellular factor incorporation into viral particles are largely unexplored for the paramyxoviruses. To better understand the involvement of cellular machinery and the major structural viral fusion (F), attachment (G), and matrix (M) proteins during NiV assembly and budding, we performed proteomics analyses on virus-like particles (VLPs) produced from several combinations of these NiV proteins. Our findings indicate indicate NiV VLPs incorporate vesicular trafficking and actin cytoskeletal factors. The involvement of these biological processes was validated by experiments indicating that perturbation of key factors in these cellular processes substantially modulated viral particle formation. These viral budding effects were most impacted when NiV-F was expressed alone or in combination with other NiV proteins, indicating that NiV-F relies heavily on these cellular processes during its role(s) in budding. These findings indicate a significant involvement of the NiV fusion protein, vesicular trafficking, and actin cytoskeletal processes in efficient viral assembly and budding.